I had to review the instructions for compiling the files associated with matmatic.  I am reviewing the older version at the moment because I believe I haven't installed the latest.  The script is run from the compile.py which creates all the different material files.  However, the mm1 files must be in a specific location, Libraries>materials>MatmaticDemos, for the script to work.  The location can be edited within the script.

Unless something has changed dramatically with the newer version, this is the instructions I have.